Final Report: Enhanced Treatment of DNAPLs Contaminated Soils and Groundwater Using Biosurfactants: In-Situ Bioremediation
EPA Grant Number: R826694C625Subproject: this is subproject number 625 , established and managed by the Center Director under grant R828598
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: Gulf Coast HSRC (Lamar)
Center Director: Ho, Tho C.
Title: Enhanced Treatment of DNAPLs Contaminated Soils and Groundwater Using Biosurfactants: In-Situ Bioremediation
Investigators: Vipulanandan, C. , Roberts, D. J.
Institution: University of Houston - University Park
EPA Project Officer: Krishnan, Bala S.
Project Period: September 1, 2000 through August 31, 2004
RFA: Gulf Coast Hazardous Substance Research Center (Lamar University) (1996)
Research Category: Hazardous Waste/Remediation , Targeted Research
Description:
Objective:The objective of this study was to enhance the removal of selected DNAPLs from contaminated soils using biosurfactants and to evaluate the potential of biodegrading DNAPLs.(1) Solubilization and biodegradtion of selected DNAPLs will be investigated. Effect of surfactant concentrations, pH, temperature and salt content will be studied. (2) Interaction between biosurfactant-soil-DNAPL will be studied in batch and column reactors. Sorption isotherms for DNAPLs and various soil components (sand, clay, organic matter) will be studied. Performance of biosurfactant will be compared to chemical surfactants. Biodegradation of DNAPLs with soil and biosurfactants will be investigated to optimize treatment parameters.(3) Model Study: Solubilization/mobilization of residual DNAPLs in homogenous soil conditions will be studied. Soil column tests will be used in this part of the study.
Summary/Accomplishments (Outputs/Outcomes):Various microorganisms and substrates were screened for the biosurfactant production. The Pseudomonas sp. was chosen as the producing microorganism and used vegetable oil was chosen as the substrate. The biosurfactant was recovered from the broth through a series of steps involving precipitation, washing, and drying. The UH-biosurfactant was characterized by the surface tension, CMC, melting point, mass spectrometry, and microscope analysis. The solubilization and adsorption of naphthalene, phenanthrene, and TCE to soil constituents were investigated. The biodegradation of naphthalene and TCE was also investigated to evaluate the effects of the surfactants on the biodegradation of the contaminants. Performance of UH-biosurfactant was compared chemical surfactants such as sodium dedecyl sulfate (SDS- anionic) and Triton X-100 (nonionic). Removal of naphthalene from 10,000 mg/kg contaminated soil column was studied. RESULTS AND DISCUSSIONS 1. Biosurfactant Production and Characterization Biosurfactant was produced in continuously stirred batch reactors. At the end of the production of biosurfactant, the pH of the broth was adjusted to 2.0 to precipitate the product and was then separated by filtering through 1 mm glass fiber membrane. At pH = 10.5, the precipitates dissolve in water and formed a clear solution. The surface tension of biosurfactant solution was 28 dynes/cm at a CMC concentration of 0.2 g/L. Various other methods of separating the UH-biosurfactant from the broth and concentrating them were also investigated. The solid biosurfactant was readily dissolved in de-ionized (DI) water (10 g/L) and the pH of the solution was above 10. When the pH of the solution was adjusted with HCl solution (0.1 N), the solution started to become turbid between pH values of 9 and 8. The solution then turned into a white dispersion after the pH was adjusted to below 7. This property was similar to that of lauric acid (a straight chain fatty acid with 12 carbon atoms), which dissolves in alkaline water (pH = 10). When HCl was added into the lauric acid solution (0.9 g/L), white dispersion was also formed due to the fact that the solubility of lauric acid in its acid form is smaller than that of its salt form. The similar behavior of the biosurfactant and lauric acid showed the possibility that the biosurfactant had similar fatty acid structure. When the pH of the biosurfactant solution was lowered, more biosurfactant molecules were converted to its acid form, causing the formation of the white dispersion. 2. Solubilization Naphthalene, phenathrene and trichloroehylene were solubilized by adding extra amount of DNAPLs into surfactant solutions. DNAPL concentrations were measured using gas chromatography. Hydrochloric acid and sodium hydroxide were used to adjust the pH when necessary. The temperature used was 22 ¢ªC. The apparent solubility of the compounds increased linearly with the surfactant concentration at surfactant concentrations above the CMC value of the surfactant. Eight hundred (800) mg/L naphthalene was solubilized by 10 g/L biosurfactant at pH = 10.5 or 5 g/L biosurfactant at pH = 7. Even though the surface activity was higher at pH = 10.5, the solubilization capability of the biosurfactant at pH = 10.5 was lower than at pH = 7; the possible reason is that at pH =7, the biosurfactant in the solution was an emulsion (milky white). This emulsion had higher solubilization potential for naphthalene. Over 150 mg/L and 7000 mg/L of phenathrene and TCE were solubilized using the UH-biosurfactant. 3. Biodegradation A crude oil degrading bacterium was used to degrade solubilized naphthalene. Centrifuging the samples from the bioreactor and analyzing naphthalene concentration using a gas chromatography monitored the biodegradation of naphthalene. Turbidity of the bioreactor was monitored using a UV-Visible Spectrophotometer at the wavelength of 540 nm to indicate the change of biomass. The pH for biodegradation was maintained between 6 and 7. Biodegradation of 30 mg/L naphthalene solubilized in water and biosurfactant solution was degraded in three days (including one day of lag phase) and the result was comparable to other published data. The biosurfactant did not affect the rate of naphthalene biodegradation. Although the biosurfactant concentration was not monitored during the biodegradation test, the turbidity change indicated that the microorganism also utilized the biosurfactant. In the case of high initial naphthalene concentration (200 mg/L and 450 mg/L), the time needed for total naphthalene degradation was much longer than low initial concentration (30 mg/L). The initial reduction in naphthalene concentration was in phase with the increase in turbidity (biomass growth). However, the rapid increase of turbidity was not the result of rapid degradation of naphthalene. Based on the observation of naphthalene particles formation after the initial period, the biosurfactant was rapidly utilized by the microorganism. The drop in biosurfactant concentration resulted in the formation of naphthalene particles in the reactors because of decreased solubilization capacity. The naphthalene particles were redissolved with the addition of biosurfactants and degraded, leading to longer time period for complete biodegradation. Triton X-100 did not have any noticeable effect on the rate of naphthalene biodegradation. No change in Triton X-100 concentration was observed during the biodegradation test, and this was in agreement with the turbidity change. No naphthalene biodegradation was detected with SDS (concentrations of 3 and 5 g/L) for 45 days. 4. Sorption The adsorption of naphthalene, phenanthrene, and TCE on various soil constituents was investigated with and without the presence of surfactants. Surfactants affected the adsorption of the contaminants in two ways. One was by modifying the aqueous solubility of the contaminants and the other by modifying the soil surfaces by adsorption of the surfactant molecules. A model was developed to describe the effects of the modifications. Linear isotherms were obtained for the adsorption of naphthalene, phenanthrene, and TCE in the current research. A linear isotherm makes it easier to represent the adsorption by a single partition coefficient (Kd) which is the slope of the isotherm. The Kd values with mulch (mainly organic matter) were much higher than that with kaolinite clay. Addition of surfactants reduced the Kd of naphthalene with the mulch. 5. Column Study Contaminated clayey soil was used for the column study. The 10,000 mg/kg contaminated soil was prepared by adding naphthalene into moist soil. Removal efficiency of 10 CMC UH-biosurfactant solution was compared to DI water. After flushing 5-pore volume of UH-biosurfactant and DI water in separate columns, the naphthalene recovered was 300% higher in the case of the biosurfactant. CONCLUSIONS Based on the experimental study following conclusions are advanced: 1. A biosurfactant was produced under non-aseptic condition by a Pseudomonas sp. utilizing used vegetable oil, a common domestic and restaurant waste. The biosurfactant was produced during the growth phase and the stationary phase. 2. The biosurfactant lowered the surface tension of water to 28 mN/m at pH = 10.5. The CMC of the biosurfactant was about 0.2 g/L based on the surface tension measurement. 3. The biosurfactant effectively solubilized more naphthalene, phenathrene and trichloroethylene at neutral pH as compared to SDS and Triton X-100. 4. Over 450 mg/L and 600 mg/L of naphthalene in biosurfactant and Triton X-100 solutions respectively were completely biodegraded by the Pseudomonas sp. 5. The biosurfactant was a competing substrate in the biodegradation of naphthalene, while Triton X-100 was not utilized by the microorganism. SDS inhibited the biodegradation of naphthalene. The competing biodegradation of the biosurfactant may have led to the longer time for naphthalene biodegradation. 6. The surfactants effectively decreased the adsorption (onto the kaolinite clay and the mulch) of naphthalene and phenanthrene at concentrations above the CMC values. The effect of the surfactants on the adsorption of the adsorbate was represented with the solid phase effectiveness factor and the aqueous phase effectiveness factor. The solid phase effectiveness factor was a function of the surfactant concentration and reached a limiting value at higher surfactant concentrations. 7. Flushing with 10 CMC biosurfactant solution removed 300% higher naphthalene after 5-pore volume as compared to DI water.
Journal Articles on this Report: 2 Displayed | Download in RIS Format
Other subproject views: | All 3 publications | 2 publications in selected types | All 2 journal articles |
Other center views: | All 472 publications | 140 publications in selected types | All 123 journal articles |
Type | Citation | ||
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|
Vipulanandan C, Ren XP. Enhanced solubility and biodegradation of naphthalene with biosurfactant. Journal of Environmental Engineering-Asce 2000;126(7):629-634 |
R826694C625 (Final) |
not available |
|
Wang SY, Vipulanandan C. "Biodegradation of naphthalene-contaminated soils in slurry bioreactors. Journal of Environmental Engineering ASCE 2001; 127(8): 748-754. |
R826694C625 (Final) |
not available |
bioremediation, DNAPLs, biosurfactants. , POLLUTANTS/TOXICS, Water, INTERNATIONAL COOPERATION, TREATMENT/CONTROL, Scientific Discipline, Waste, RFA, Remediation, Chemicals, Hazardous Waste, Environmental Engineering, Environmental Chemistry, Chemistry and Materials Science, Contaminated Sediments, Groundwater remediation, Hazardous, Treatment Technologies, Bioremediation, anaerobic biodegradation, chemical transport, groundwater, contaminated sediment, DNAPLs, used vegetable oil, chlorinated solvents, contaminant transport, in-situ bioremediation, anaerobic biotransformation, contaminated soil, groundwater contamination, DNAPL, anaerobic degradation, advanced treatment technologies, contaminated groundwater, hazardous waste treatment, sediment treatment, biosurfactants, chemical contaminants, in situ bioremediation
Relevant Websites:
Progress and Final Reports:
Original Abstract
Main Center Abstract and Reports:
R828598 Gulf Coast HSRC (Lamar)
Subprojects under this Center:
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R822721C529 Environmentally Acceptable Endpoints: Risk Based Remediation Using Bioremediation
R822721C552 Degradative Solidification/Stabilization Technology for Chlorinated Hydrocarbons
R822721C569 Treatment and Product Recovery: Supercritical Water Oxidation of Nylon Monomer Manufacturing Waste
R822721C620 Colloidal Fouling of Membranes: Implications in the Treatment of Textile Dye Wastes and Water Reuse
R822721C626 Catalytic Hydroprocessing of Chlorinated Organics
R822721C627 The Interaction of Microbial Activity and Zero Valent Iron Permeable Barrier Technology
R822721C630 Microbial Cometabolism of Recalcitrant Chemicals in Contaminated Air Streams
R822721C633 Catalyst Lifetime Studies for Chlorocarbon Steam Reforming
R822721C635 Electrokinetic/Surfactant-Enhanced Remediation of Hydrophobic Pollutants in Low Permeability Subsurface Environments
R822721C636 Transformation Reactions of Nitroaromatic and Nitrogen Heterocyclic Compounds on Granular Activated Carbon (GAC) Surfaces: Enhancement of GAC Adsorption in Natural and Engineered Environmental Systems
R822721C640 Environmentally Friendly Organic Synthesis in Supercritical Fluids
R822721C645 Development and Evaluation of an Integrated Model to Facilitate Risk-Based Corrective Action at Superfund Sites
R822721C651 Adjustable Biopolymer Chelators for Cadmium, Lead and Mercury
R822721C653 New Electrochemically Smart Catalysts for Hazardous Waste Management and Development of Capillary Electrophoresis for Analysis of their Products
R822721C655 Soil Sampling in South Alabama Oil Fields
R822721C659 Subsurface Contamination Site Characterization via a Computer-Aided Visual Tool
R822721C661 New Insoluble supports for Protein Immobilization for Use in Metalloprotein Affinity Metal Chromatography
R822721C663 Soil Remediation with Ultra-High-Efficiency Hydrocyclones
R822721C669 Solid Acid Catalyzed Alkylation in Supercritical Fluids
R822721C679 Regeneration/Reactivation of Carbon Adsorbents by Radio Frequency (RF) Induction Heating
R822721C687 Improved Halogen Resistance of Catalytic Oxidation
R822721C696 Phytoremediation and Bioremediation of Land Contaminated By PAHs, PCBs, and TNT
R822721C697 Fundamental and Kinetic Investigation of Sorbent Technology for Optimum Mercury Emission Control
R822721C700 Effects of Natural and Cyclic Variations on Contaminant Fate and Transport
R822721C703 Enhancement of DNAPL Dissolution Rates by Dechlorinating Anaerobes
R826694C620 Colloidal Fouling of Membranes: Implications in the Treatment of Textile Dye Wastes and Water Reuse
R826694C625 Enhanced Treatment of DNAPLs Contaminated Soils and Groundwater Using Biosurfactants: In-Situ Bioremediation
R826694C626 Catalytic Hydroprocessing of Chlorinated Wastes
R826694C627 The Interaction of Microbial Activity and Zero Valent Iron Permeable Barrier Technology
R826694C629 Biofiltration of BTEX in Petroleum-Contaminated Soil Remediation Off-Gas
R826694C630 Microbial Cometabolism of Recalcitrant Chemicals in Contaminated Air Streams
R826694C633 Catalyst Lifetime Studies for Chlorocarbon Steam Reforming
R826694C635 Electrokinetic/Surfactant-Enhanced Remediation of Hydrophobic Pollutants in Low Permeability Subsurface Environments
R826694C636 Transformation Reactions of Nitroaromatic and Nitrogen Heterocyclic Compounds on Granular Activated Carbon (GAC) Surfaces: Enhancement of GAC Adsorption in Natural and Engineered Environmental Systems
R826694C640 Environmentally Friendly Organic Synthesis in Supercritical Fluids
R826694C645 Development and Evaluation of an Integrated Model to Facilitate Risk-Based Corrective Action at Superfund Sites
R826694C651 Adjustable Biopolymer Chelators for Cadmium, Lead, and Mercury Remeidation
R826694C659 Subsurface Contamination Site characterization Via a Computer-Aided Visual Tool
R826694C661 New Insoluble supports for Protein Immobilization for Use in Metalloprotein Affinity Metal Chromatography
R826694C669 Solid Acid Catalyzed Alkylation in Supercritical Reaction Media
R826694C679 Regeneration and Reactivation of Carbon Adsorbents by Radio Frequency Induction Heating
R826694C696 Phytoremediation and Bioremediation of Land Contaminated By PAHs, PCBs, and TNT
R826694C697 Fundamental and Kinetic Investigation of Sorbent Technology for Optimum Mercury Emission Control
R826694C700 Effects of Natural Cyclic Variations on Contaminated Fate and Transport
R826694C703 Enhancement of DNAPL Dissolution Rates by Dechlorinating Anaerobes
R826694C705 A Pilot Plant for Producing Mixed Ketones from Waste Biomass
R826694C722 The Effects of an Oily-Phase on VOC Emissions from Industrial Wastewater
R826694C724 Mercury Removal from Stack Gas by Aqueous Scrubbing
R826694C725 Transport, Fate and Risk Implications of Environmentally Acceptable Endpoint Decisions
R826694C731 Development and Application of a Real-Time Optical Sensor for Atmospheric Formaldehyde
R826694C734 An Advanced System for Pollution Prevention in Chemical Complexes
R828598C001 Field Study Abstract: A Model of Ambient Air Pollution in Southeast Texas Using Artificial Neural Network Technology
R828598C002 Hollow Fiber Membrane Bioreactors for Treating Water and Air Streams Contaminated with Chlorinated Solvents
R828598C003 Fugitive Emissions of Hazardous Air Pollutants from On-Site Industrial Sewers
R828598C004 Biofiltration Technology Development
R828598C005 A Risk-Based Decision Analysis Approach for Aquifers Contaminated with DNAPLs
R828598C006 In-Situ Remediation for Contaminated Soils Using Prefabricated Vertical Drains
R828598C007 Membrane Technology Selection System for the Metal Finishing Industry
R828598C008 Sequential Environments for Enhanced Bioremediation of Chlorinated Aliphatic Hydrocarbons
R828598C009 Waste Minimization in the Magnetic Tape Industry: Waterborne Coating Formulations for Magnetic Tape Manufacture
R828598C010 Soil Remediation by Agglomeration with Petroleum Coke
R828598C011 Recovery of Dilute Phosphoric Acid in Waste Streams Using Waste Gas Ammonia: The Regenerative MAP/DAP Process
R828598C012 Stochastic Risk Assessment for Bioremediation
R828598C013 Selective Removal of Heavy Metals from Wastewater by Chelation in Supercritical Fluids
R828598C014 Optimization of Treatment Technologies for Detoxification of PCB Contaminated Soils
R828598C015 Wastewater Remediation by Catalytic Wet Oxidation
R828598C016 Permanence of Metals Containment in Solidified and Stabilized Wastes
R828598C017 Combustion Enhancement by Radial Jet Reattachment - Low Generation of Hazardous Gases and High Thermal Efficiency
R828598C018 A Process To Convert Industrial Biosludge and Paper Fines to Mixed Alcohol Fuels
R828598C019 Homogeneous Catalysis in Supercritical Carbon Dioxide
R828598C020 Ultrasonic Enhancement of the Removal of Heavy Metals
R828598C021 The Binding Chemistry and Leaching Mechanisms of Advanced Solidification/Stabilization Systems for Hazardous Waste Management
R828598C022 Development of an Air-Stripping and UV/H2O2 Oxidation Integrated Process To Treat a Chloro-Hydrocarbon-Contaminated Ground Water
R828598C023 A Comparative Study of Siting Opposition in Two Counties
R828598C024 Sonochemical Treatment of Hazardous Organic Compounds II: Process Optimization and Pathway Studies
R828598C025 Laser Diagnostics of the Combustion Process within a Rotary Kiln Incinerator
R828598C026 Use of Inorganic Ion Exchangers for Hazardous Waste Remediation
R828598C027 Kaolinite Sorbent for the Removal of Heavy Metals from Incinerated Lubricating Oils
R828598C028 Destruction of Chlorinated Hydrocarbons in Process Streams Using Catalytic Steam Reforming
R828598C029 Integrated Process Treatment Train (Bioremediation {Aerobic/Anaerobic} and Immobilization) for Texas Soils Contaminated with Combined Hazardous Wastes
R828598C030 Photo-Oxidation by H2O2/VisUV of Off-Gas Atmospheric Emissions from Industrial and Environmental Remediation Sources
R828598C031 Concentrated Halide Extraction and Recovery of Lead from Soil
R828598C032 Biodegradable Surfactant for Underground Chlorinated Solvent Remediation
R828598C033 A Software Guidance System for Choosing Analytical Subsurface Fate and Transport Models Including a Library of Computer Solutions for the Analytical Models
R828598C034 Hydrodynamic Modeling of Leachate Recirculating Landfill
R828598C035 Measurement of Oxygen Transfer Rate in Soil Matrices
R828598C036 Sorbent Technology for Multipollutant Control During Fluidized Bed Incineration
R828598C037 Pollution Prevention by Process Modification Using On-Line Optimization
R828598C038 Pollution Prevention by Process Modification
R828598C039 Water Solubility and Henry's Law Constant
R828598C040 Transferring Technical Information on Hazardous Substance Research by Publishing on the World Wide Web
R828598C041 Stress Protein Responses to Multiple Metal Exposure in Grass Shrimp
R828598C042 Life-Cycle Environmental Costing for Managing Pollution Prevention in the Chemical and Petroleum Refining Industries: A Cross-Border Approach
R828598C687 Improved Halogen Resistance of Catalytic Oxidation Through Efficient Catalyst Testing
R828598C696 Phytoremediation and Bioremediation of Land Contaminated By PAHs, PCBs, and TNT
R828598C697 Fundamental and Kinetic Investigation of Sorbent Technology for Optimum Mercury Emission Control
R828598C700 Effects of Natural Cyclic Variations on Contaminated Fate and Transport
R828598C703 Enhancement of DNAPL Dissolution Rates by Dechlorinating Anaerobes
R828598C705 A Pilot Plant for Producing Mixed Ketones from Waste Biomass
R828598C722 The Effects of an Oily-Phase on VOC Emissions from Industrial Wastewater
R828598C724 Mercury Removal from Stack Gas by Aqueous Scrubbing
R828598C725 Transport, Fate and Risk Implications of Environmentally Acceptable Endpoint Decisions
R828598C731 Development and Application of a Real Time Optical Sensor for Atmospheric Formaldehyde
R828598C734 An Advanced System for Pollution Prevention in Chemical Complexes
R828598C743 Field Demonstration of Ultrasound Enhancement of Permeable Treatment Walls
R828598C744 Optical Fibers Coated With Titania Membrane/UV-Generating Crystal in a Distributed-Light Photoreactor for VOC Oxidation
R828598C749 Characterization and Modeling of Indoor Particulate Contaminants In a Heavily Industrialized Community
R828598C753 Adsolubilization and Photocatalysis in a Semiconducting Monolithic Reactor for Wastewater Treatment
R828598C754 Remote Detection of Gas Emissions in Industrial Processes
R828598C759 Searching for Optimum Composition of Phosphogypsum: Fly ash: Cement Composites for Oyster Culch Materials
R828598C761 Development of a Phytologically-Based Biosorptive Water Treatment Process
R828598C766 Chlorinated Solvent Impact and Remediation Strategies for the Dry Cleaning Industry
R828598C769 Soil/Sediment Remediation by Hot Water Extraction Combined with In-Situ Wet Oxidation
R828598C771 Fluoracrylate Polymer Supported Ligands as Catalysts for Environmentally Benign Synthesis in Supercritical Fluids
R828598C774 The Feasibility of Electrophoretic Repair of Impoundment Leaks
R828598C777 Surfactant Enhanced Photo-oxidation of Wastewaters
R828598C778 Stationary Power Generation Via Solid Oxide Fuel Cells: A Response to Pollution and Global Warming
R828598C786 Photocatalytic Recovery of Sulfur and Hydrogen From Hydrogen Sulfide
R828598C787 Biosurfactant Produced from Used Vegetable Oil for removal of Metals From Wastewaters and Soils
R828598C789 Genetic Engineering of Enzymatic Cyanide Clearance
R828598C791 Characterizing the Intrinsic Remediation of MTBE at Field Sites
R828598C799 Simultaneous Water Conservation/Recycling/Reuse and Waste Reduction in Semiconductor Manufacturing
R828598C801 Building Defined Mixed Cultures To Biodegrade Diverse Mixtures Of Chlorinated Solvents
R828598C802 Engineering of Nanocrystal Based Catalytic Materials for Hydroprocessing of Halogenated Organics
R828598C807 Commercial Demonstration of Hydrogen Peroxide Injection to Control NOx Emissions from Combustion Sources
R828598C809 Evaluating Source Grouting and ORC for Remediating MTBE Sites
R828598C810 Application of Total Cost Assessment To Process Design In the Chemical Industry
R828598C846 Quantitative Demonstration of Source-Zone Bioremediation in A Field-Scale Experimental Controlled Release System
R831276C001 DNAPL Source Control by Reductive Dechlorination with Fe(II)
R831276C002 Arsenic Removal and Stabilization with Synthesized Pyrite
R831276C003 A Large-Scale Experimental Investigation of the Impact of Ethanol on Groundwater Contamination
R831276C004 Visible-Light-Responsive Titania Modified with Aerogel/Ferroelectric Optical Materials for VOC Oxidation
R831276C005 Development of a Microwave-Induced On-Site Regeneration Technology for Advancing the Control of Mercury and VOC Emissions Employing Activated Carbon
R831276C006 Pollution Prevention through Functionality Tracking and Property Integration
R831276C007 Compact Nephelometer System for On-Line Monitoring of Particulate Matter Emissions
R831276C008 Effect of Pitting Corrosion Promoters on the Treatment of Waters Contaminated with a Nitroaromatic Compounds Using Integrated Reductive/Oxidative Processes
R831276C009 Linear Polymer Chain and Bioengineered Chelators for Metals Remediation
R831276C010 Treatment of Perchlorate Contaminated Water Using a Combined Biotic/Abiotic Process
R831276C011 Rapid Determination of Microbial Pathways for Pollutant Degradation
R831276C012 Simulations of the Emission, Transport, Chemistry and Deposition of Atmospheric Mercury in the Upper Gulf Coast Region
R831276C013 Reduction of Environmental Impact and Improvement of Intrinsic Security in Unsteady-state
R831276C014 Integrated Chemical Complex and Cogeneration Analysis System: Greenhouse Gas Management and Pollution Prevention Solutions
R831276C015 Improved Combustion Catalysts for NOx Emission Reduction
R831276C016 A Large-Scale Experimental Investigation of the Impact of Ethanol on Groundwater Contamination
R831276C017 Minimization of Hazardous Ion-Exchange Brine Waste by Biological Treatment of Perchlorate and Nitrate to Allow Brine Recycle
R831276C018 Integrated Chemical Complex and Cogeneration Analysis System: Greenhouse Gas Management and Pollution Prevention Solutions